CVE-2012-6099 in moodle
Summary
by MITRE
The moodle1 backup converter in backup/converter/moodle1/lib.php in Moodle 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 does not properly validate pathnames, which allows remote authenticated users to read arbitrary files by leveraging the backup-restoration feature.
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Analysis
by VulDB Data Team • 02/25/2019
The vulnerability identified as CVE-2012-6099 affects Moodle learning management systems across multiple versions including 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1. This issue resides within the moodle1 backup converter component located in backup/converter/moodle1/lib.php, representing a critical security flaw that undermines the integrity of the backup and restoration functionality. The vulnerability stems from inadequate pathname validation mechanisms that fail to properly sanitize user-supplied input during the backup conversion process.
The technical flaw manifests through improper validation of pathnames within the backup conversion logic, allowing authenticated users to exploit the system through maliciously crafted file paths. Attackers can leverage the backup-restoration feature to perform arbitrary file reads by manipulating the pathname parameters that are processed during the conversion of moodle1 backup files to the current Moodle format. This weakness enables attackers to traverse the file system and access sensitive files that should remain protected, potentially exposing configuration details, user credentials, or other confidential information stored on the server.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to escalate privileges and potentially compromise the entire Moodle installation. Since the vulnerability requires authentication, it limits the attack surface to legitimate users who already have access to the system, but it significantly increases the potential damage that authenticated users can inflict. The attack vector is particularly concerning because it leverages legitimate system functionality, making detection more difficult and allowing attackers to remain undetected while accessing sensitive data. This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and represents a classic example of path traversal attacks that have been documented in numerous security frameworks.
Organizations using affected Moodle versions face significant risks including unauthorized data access, potential privilege escalation, and exposure of sensitive institutional information. The vulnerability affects the core backup and restore functionality that is essential for educational institutions, making it particularly dangerous in academic environments where user data privacy is paramount. Security practitioners should note that this vulnerability demonstrates the importance of input validation in system components that handle file operations, especially those that process user-supplied data within privileged contexts. The remediation approach requires immediate patching of affected Moodle installations to the latest stable versions, along with implementing additional access controls and monitoring mechanisms to detect potential exploitation attempts. This vulnerability also highlights the need for comprehensive security testing of backup and restoration features, as these components often receive less scrutiny than core application functionality and may contain critical security flaws that can be exploited by authenticated users.